Pressurised container

ABSTRACT

The invention can be used for the pressurized storage of gases. The aim of the invention is to provide a pressurized container consisting of fibre-reinforced plastic with flat or practically flat lids. To achieve this, wound axially aligned reinforcement structures run through the interior of the body and absorb the major part of the required forces on their plane of alignment. The invention is characterized in that fibre strands are distributed uniformly over the cross-sectional surface of the cylindrical pressurized container, are aligned axially and fixed to flat or practically flat lids. In one advantageous embodiment of the invention, a container is formed by the spiral winding of an essentially unidirectional fibre-layer, which is thicker at its edges. Reinforcement layers, which are arranged in a circumferential direction and exert a radial action, cover the reinforcement strands or the spirally wound unidirectional fibre-layer, said layers forming the casing of the pressurized container.

The invention refers to a pressurized container of fibre-reinforcedplastic for the storage of gases.

BACKGROUND OF THE INVENTION

The prior art is characterized by pressurized container which contain aninternal liner of metal or plastic. The fibre-reinforced plastic isapplied to the internal liner by means of a winding method (concerningthis see DE-OS 199 52 611). When applying this method the axial strengthis obtained by longitudinal windings and the circumferential windings isobtained separately by circumferential windings.

As an essential element of the vessels the internal liner serves as asupporting frame for the application of the fibre-reinforced plastic aswell as a barrier to permeation of gases. The strength of thepressurized container is achieved by application of fibre-reinforcedplastic.

The disadvantage of the design described above is that the internalliner increases the weight of the component. Moreover, an unfavorablematerial distribution arises in the areas of the domes, because anon-strength-causing accumulation of material occurs in the area of thepoles of the domes by the winding process. A problem which stands in theway of using the biggest possible volume of the known vessels refers tothe fact that the front sides of the pressurized container are alwaysshaped as convex domes. Due to the shape of the domes an unfavorable useof volume is given.

A modification of the domes by a so-called isotensoid shape and amodification of the distribution of fibers and angles can only partlydefuse this problem.

Due to the arrangement of fibre cords in the area of the periphery orjacket of the pressurized container and due to the winding processforces have to be absorbed from several directions.

BRIEF SUMMARY OF THE INVENTION

The invention is based on the problem to develop a pressurized containerwhich makes possible a substantial improvement in design of thepressurized container with little expenditure. For this purpose apressurized container of fibre-reinforced plastic with plane or almostplane covers shall be developed by which the above-mentioneddisadvantages will be reduced.

According to the invention this problem is solved in such a way that atleast in one direction there are arranged axially aligned reinforcementstructures going through the interior of the pressurized container andwhich are equally distributed in the interior and absorb the major partof the forces caused by the inside pressure.

The invention is characterized by the feature that fibre cords offibre-reinforced composite materials (preferably carbon fibers andimpregnated with a matrix of epoxy resin), which are arranged equallydistributed over the cross-sectional area of the cylindrical pressurizedcontainer, are exactly axially aligned and are fixed to plane or largelyplane covers.

It is intended by an advantageous further development that a vesselshall be created by the spiral winding-up of a largely unidirectionalfibre layer which is thickened at the ends.

The fibre orientation of the layer on the area is across the windingdirection. The thickened spots may also be oriented in a differentdirection or made of a different material.

Over the reinforcement cords or the spirally winded-up unidirectionalfibre layer there will be applied circumferentially aligned, radiallyacting reinforcement layers which form the seal of the pressurizedcontainer. Another aspect of the invention is that an axialreinforcement is effected in more than one direction. Furthermore, it isintended to combine a combination of axial reinforcements going throughthe interior with reinforcements, which are integrated in the outerjacket.

It is intended by one design, for increasing the gas tightness of thepressurized container to wind up barrier layers between the outer layerof axial reinforcement and the circumferentially winded outer jacket,which are largely overlapping each other.

The use of the almost plane covers of the vessels was found to besurprising and provides a technical solution which makes it possible totranslate into reality a number of advantages when designing the windedpressurized container.

For fixing the covers on both sides, an inside gas-open reinforcing pipepresents itself.

The covers which form the front sides of the pressurized containerconsist of suitable light metallic materials or of fibre-reinforcedplastic. For integrating the reinforcement structures slots may be madeat regular angles, but at different depths. At the same time thesolution is made possible by this, to connect the fittings of thepressurized container in a gas-tight manner with the gas connections.

The invention is characterized by a number of advantages:

No internal liner is required.

The reinforcing materials are almost completely oriented to thedirection of the forces appearing. From both features a clearimprovement of the weight-specific storage capacity is resulting. Themanufacture is simplified.

An integration into plants is possible in a more space-saving way due toa more favorable shaping design and thus an increase of the volumetricstorage density is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

Accompanying the specification are figures which assist in illustratingthe embodiments of the invention, in which:

FIG. 1 Pressurized container with fibre cords;

FIG. 2 Pressurized container with unidirectional layers; and

FIG. 3 Unidirectional layers.

DETAILED DESCRIPTION OF THE INVENTION

The pressurized container as shown by FIG. 1 is created by arrangementof axially through-going reinforcement structures 1, which consist offibre cords of fibre-reinforced composite materials, preferablyimpregnated single threads of carbon fibers or other high-strengththread-shaped cords, inside a cylinder. They are largely equallydistributed over the cross-sectional area and are anchored on planecovers 7. The covers 7 are also made from the cord material by means ofa winding technology or are wrapped up by a different material.Preferably in the center of the covers, a metallic connection 5 for thefittings is embedded into the composite material.

In the outer bounds of the pressure space these reinforcement cords arearranged very closely, so that they can be covered with a barrier layer3. Onto this layer then the radial reinforcements 2 are winded up, whichresult in the radial reinforcement and form the outer seal of thepressurized container.

The pressurized container as shown by FIGS. 2 and 3 is created bywinding up a semi-finished product consisting of a ground coat ofunidirectional layers (coat-type layers of fibre-reinforced compositematerials, preferably carbon fibers impregnated with a matrix of epoxyresin), with thickened spots 8 applied at the ends. These thickenedspots are also preferably created by composite material and mayadditionally contain barrier layers 6.

The semi-finished product is usually pre-impregnated with a matrixsystem. Winding up may be done on a metallic reinforcing pipe 4 which atthe same time carries the fittings. For this purpose the pipe must have4 openings for flowing through of the storage medium.

When winding up the semi-finished product is oriented in such a way thatthe direction of fibers in the ground coat corresponds with the axialdirection of the pressure body.

The thickened spots 8 on the edge area just form the axial border of thepressure body.

Onto the spiral-shaped core created a barrier layer 3 acting in radialdirection can be applied.

On this layer then a radially acting reinforcing layer 2 oriented tocircumferential direction will be lying.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not as restrictive. The scope of the invention is, therefore,indicated by the appended claims and their combination in whole or inpart rather than by the foregoing description. All changes that comewithin the meaning and range of equivalency of the claims are to beembraced within their scope.

1-10. (canceled)
 11. A pressurized cylindrical container comprising:axially reinforcing structures for absorbing forces from internalpressure in said pressurized container, said axially reinforcingstructures disposed interior of said pressurized container; said axiallyreinforcing structures consist of fiber cords, said fiber cords equallydistributed over a cross-sectional area of said pressurized container;said fiber cords being exactly axially aligned, mutually parallel andenclosed by a radial reinforcement layer; and said radial reinforcementlayer being circumferentially aligned.
 12. The pressurized container ofclaim 11 wherein: said axial reinforcing structures consist ofspiral-shaped winded up unidirectional layers of a composite material;said axial reinforcing structures have thickened spots at an end of saidlayers of composite material; said axial reinforcing structures formingcovers; and said axial reinforcing structures being enclosed by saidradial reinforcement layer.
 13. The pressurized container of claim 12wherein barrier layers disposed between an outer layer of said axialreinforcing structures and said radial reinforcement layer, said barrierlayers reducing permeation of gases.
 14. The pressurized container ofclaim 12 further comprising a wound up cord-shaped overlapping barrierlayer.
 15. The pressurized container of claim 14 further comprising:covers including slots, said slots being successively disposed at apredetermined constant angle, said successive slots having differingdepths; and said axial reinforcing structures being fixed in said slots.16. The pressurized container of claim 15 wherein fittings are connectedgas-tight with said covers.